Applications of Raman Spectroscopy in Metamorphic Petrology and Tectonics

Elements ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 105-110 ◽  
Author(s):  
Andrey V. Korsakov ◽  
Matthew J. Kohn ◽  
Maria Perraki
Keyword(s):  
Raman Spectroscopy ◽  
Sample Preparation ◽  
Chemical Equilibrium ◽  
Carbonaceous Material ◽  
Ultrahigh Pressure ◽  
Metamorphic Rocks ◽  
Temperature Sensitive ◽  
Metamorphic Petrology ◽  
Minimal Sample ◽  
Tectonic Processes

Raman spectroscopy is widely applied in metamorphic petrology and offers many opportunities for geological and tectonic research. Minimal sample preparation preserves sample integrity and microtextural information, while use with confocal microscopes allows spatial resolution down to the micrometer level. Raman spectroscopy clearly distinguishes mineral polymorphs, providing crucial constraints on metamorphic conditions, particularly ultrahigh-pressure conditions. Raman spectroscopy can also be used to monitor the structure of carbonaceous material in metamorphic rocks. Changes in structure are temperature-sensitive, so Raman spectroscopy of carbonaceous material is widely used for thermometry. Raman spectroscopy can also detect and quantify strain in micro-inclusions, offering new barometers that can be applied to understand metamorphic and tectonic processes without any assumptions about chemical equilibrium.

scholarly journals Pyrite and pyrrhotite in a prograde metamorphic sequence, Hyland River region, SE Yukon: implications for orogenic gold

2021 ◽  
Author(s):  
C D W Padget ◽  
D R M Pattison ◽  
D P Moynihan ◽  
O Beyssac
Keyword(s):  
Raman Spectroscopy ◽  
Phase Equilibrium ◽  
Source Region ◽  
Carbonaceous Material ◽  
Orogenic Gold ◽  
Metamorphic Rocks ◽  
Small Interval ◽  
River Region ◽  
Gradual Release ◽  
Fluid Release

The distribution of pyrite and pyrrhotite is documented within an andalusite-sillimanite type (high-temperature, low-pressure) metasedimentary succession exposed in the Hyland River region of southeastern Yukon, Canada. The following metamorphic zones are recognized: chlorite, biotite, cordierite/staurolite (porphyroblast-in), andalusite, sillimanite, and K-feldspar + sillimanite. Pyrite occurs in the chlorite zone through the biotite zone, while pyrrhotite occurs from the chlorite zone to K-feldspar + sillimanite zone. The pyrite-pyrrhotite transition, therefore, occupies an interval in the chlorite and lower biotite zones that is terminated upgrade by a pyrite-out isograd in the upper part of the biotite zone or lowest grade part of the cordierite/staurolite zone. Pressure and temperature conditions of the rocks were estimated from phase equilibrium modelling and from Raman spectroscopy of carbonaceous material (RSCM) thermometry. Modelling indicates pressures of 3.7-4.1 kbar with temperatures of ~425 °C at the biotite isograd, 560-570 °C for chlorite-out/porphyroblast-in, ~575 °C for andalusite-in, 575-600 °C for the sillimanite isograd, and 645-660 °C at the K-feldspar + sillimanite isograd. RSCM temperatures are greater than or equal to 420 °C in the Chl zone, 500 °C at the Bt isograd, 525-550 °C for porphyroblast-in isograd, ~550 °C at the And isograd, and 580 °C at the Sil isograd. These results suggest the pyrite-pyrrhotite transition occurs from less than or equal to 420°C to ~560 °C. Thermodynamic modelling shows 0.6 wt. % H2O is released during metamorphism over the ~140 °C interval of the pyrite-pyrrhotite transition. The gradual release of fluid in the biotite zone is interpreted to have broadened the pyrite-pyrrhotite transition compared to other studies that predict a small interval of vigorous fluid release associated with volumetric chlorite consumption. Samples from the pyrite-pyrrhotite transition zone contain lower whole rock and pyrite Au values than samples from unmetamorphosed/lower rocks, suggesting that Au was removed from the rock at conditions below the pyrite-pyrrhotite transition (<420 °C). The chlorite zone and higher-grade metamorphic rocks of the Hyland River area do not appear to be a plausible source region for orogenic gold.

Compositional assessment of bone by Raman spectroscopy

The Analyst ◽  
2021 ◽  
Author(s):  
Mustafa Unal ◽  
Rafay Ahmed ◽  
Anita Mahadevan-Jansen ◽  
Jeffry Nyman
Keyword(s):  
Raman Spectroscopy ◽  
Sample Preparation ◽  
Physiochemical Properties ◽  
Minimal Sample ◽  
Non Destructive

Raman spectroscopy (RS) is used to analyze the physiochemical properties of bone because it is non-destructive and requires minimal sample preparation. With over two decades of research involving measurements of...

Fast and accurate shale maturity determination by Raman spectroscopy measurement with minimal sample preparation

2017 ◽  
Vol 173 ◽  
pp. 150-157 ◽  
Author(s):  
Bastian Sauerer ◽  
Paul R. Craddock ◽  
Mohammed D. AlJohani ◽  
Khalid L. Alsamadony ◽  
Wael Abdallah
Keyword(s):  
Raman Spectroscopy ◽  
Sample Preparation ◽  
Spectroscopy Measurement ◽  
Minimal Sample

Influence of Sample Preparation on Intrinsic Stress Inside a Model Chip—Comparison of Results from Electric Read-Out and Raman Spectroscopy

2017 ◽  
Author(s):  
T. Schaffus ◽  
H. Pfaff ◽  
P. Albert ◽  
M. Schaffus ◽  
F. Kroninger ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Sample Preparation ◽  
Intrinsic Stress ◽  
Stress Monitoring ◽  
Preparation Methods ◽  
Comparison Of Results ◽  
The Given

Abstract The given project is to benchmark typical preparation methods under the aspect of the influence of initial intrinsic stresses inside electric components. Raman spectroscopy has been applied as well as the piezo resistive readout on a specifically designed model stress monitoring chip.

No lyse no wash flow cytometry for maximizing minimal sample preparation

Methods ◽  
2018 ◽  
Vol 134-135 ◽  
pp. 149-163 ◽  
Author(s):  
Jordi Petriz ◽  
Jolene A. Bradford ◽  
Michael D. Ward
Keyword(s):  
Flow Cytometry ◽  
Sample Preparation ◽  
Minimal Sample

Two-Stage Exhumation of Ultrahigh-Pressure Metamorphic Rocks from the Western Dabie Orogen, Central China

2011 ◽  
Vol 119 (1) ◽  
pp. 15-31 ◽  
Author(s):  
Yuanbao Wu ◽  
Shan Gao ◽  
Xiaochi Liu ◽  
Jing Wang ◽  
Min Peng ◽  
...  
Keyword(s):  
Central China ◽  
Ultrahigh Pressure ◽  
Metamorphic Rocks ◽  
Two Stage ◽  
Dabie Orogen
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